regression from nolock mode

libs/libks/src/ks_hash.c

@@ -558,7 +558,9 @@ ks_hash_destroy(ks_hash_t **h)
     ks_pool_safe_free(pool, (*h)->table);
 	ks_hash_write_unlock(*h);
 	if ((*h)->rwl) ks_pool_free(pool, (*h)->rwl);
+	if ((*h)->mutex) {
 		ks_pool_free(pool, (*h)->mutex);
+	}
 	ks_pool_free(pool, *h);
 	pool = NULL;
 	*h = NULL;

libs/libks/test/testhash.c

@@ -132,7 +132,7 @@ int test3(void)
 	char *A, *B, *C;
 
 	ks_pool_open(&pool);
-	ks_hash_create(&hash, KS_HASH_MODE_ARBITRARY, KS_HASH_FLAG_NONE, pool);
+	ks_hash_create(&hash, KS_HASH_MODE_ARBITRARY, KS_HASH_FLAG_NOLOCK, pool);
 	ks_hash_set_keysize(hash, TEST3_SIZE);
 
 	randombytes_buf(data, sizeof(data));